I think it's Barnet (the clutch one, not the HD dealer) that makes custom length cables.
Use the tiewraps to tie the pencil to the forks, crossint the wraps over the pencil in an X to hold it securely while being able to move the pencil in and out and slide the whole thing up and down the fork by hand. align the pencil as close as possible to the rim and then slowly turn the wheel while watching the alignment with the pencil. I'm not sure what the spec is for these bikes, but usually 3/32 is the absolute max for runout and out of round.
While you're there, lock the fork and give the whell a shake to make sure the bearings aren't loose and also make sure there isn't a gritty feel while turning the wheel.
I should have paid more attention to which bike you have. If it's an America, take a screwdriver or small wrench and tap each spoke while there is no weight on the wheel to make sure they all sound about the same. There can be some varience because the spoke tension is used to true a slightly off rim, but a very high pitched 'ping' indicates a very tight spoke and a low pitch or dull clunk is a spoke that is too loose or about to break.
